A ball thrown upwards reaches a maximum height and then comes back down to the original level. As the ball is going downwards the velocity and acceleration both point up. the velocity points up and the acceleration down. the velocity points down and the acceleration up. the velocity and acceleration both point down. the acceleration is zero.

6. A ball is thrown upward with a velocity of 4.5 m/s. Its speed and the magnitude of its acceleration at the highest point (a) are both equal to zero (b) are given by 9.81 m/s and 0 m/s², respectively (c) are given by 0 m/s and 9.81 m/s², respectively (d) cannot be predicted unless the height is known Answer: 7. Which of the following statements about a projectile is not true? Assume that the air resistance is negligible. (a) Its motion is in two dimensions. (b) The only acceleration is in the vertical direction. (c) Its velocity in the horizontal direction remains the same throughout the flight. (d) The velocity at the highest point of its trajectory is zero. Answer:

True or false: If an object accelerates from rest covering 2.0m in 1.0s in the forwards direction then, even though its average velocity is 2.0m/s its instantaneous velocity (or vf in your equations) will be 4.0m/s at t=1.0s and its initial velocity (vi in your equations) will be 0.0m/s at t=0

A missile silo is used to launch military rockets vertically upward out of the silo, giving the rocket an initial speed of 79.6 m/s at ground level. As the rocket clears the silo, the engines fire, and the rocket accelerates upward at 3.90 m/s2 until it reaches an altitude of 1,080 m. At that point its engines fail, and the rocket goes into free fall, with an acceleration of -9.80 m/s². (You will need to consider the motion while the engine is operating and the free-fall motion separately. Due to the nature of this problem, do not use rounded intermediate values in your calculations-including answers submitted in WebAssign.) (a) Determine the velocity of the rocket (in m/s) at the end of the engine burn time and also the burn time (in s). (For the velocity, indicate the direction with the sign of your answer.) velocity at end of engine V = 92.22 Check your kinematic equation relating vo, V1, ay, and AYo → 1 (where velocity of rocket as it clears the silo, v, = velocity of the rocket at…